Plain words

One or two sentences each. Use them as a starting point and fit them to the moment.

Word	In plain words
Repository (repo)	The project’s folder online, with every version of every file kept, so nothing is ever really lost.
Commit	A saved snapshot of the project with a note saying what changed.
Branch	A separate copy to work on without touching the live version.
Pull request (PR)	A proposed change waiting for your OK, like a tracked-changes document.
Merge	Accepting a pull request, so the change becomes part of the main version.
Issue	A to-do card on the project’s board: a task, a bug or a question.
Label	A coloured tag on an issue that says who has it and what stage it’s at.
Deploy	Putting a version of the app online where people can use it.
Preview	A private test copy of a change, online, so you can try it before it goes live.
Production	The live version real users see.
Hosting	The rented computer on the internet where the app runs.
Database	Where the app keeps its information, like a set of spreadsheets the app reads and writes.
Domain	The web address, like a street address for the app.
API	The way one program asks another for something, like a waiter taking orders between you and the kitchen.
API key	A password that lets the app use a paid service. Treat it like a bank card PIN.
Secret / environment variable	A setting kept outside the code, such as a key, so it never shows up in the project files.
Test	A small program that checks the app does what it should, every time anything changes.
CI (checks)	The robot that runs every test on each change and puts a green tick or a red cross on it.
Spec	The written description of what to build and how we’ll know it works.
Bug	Something the app does that it shouldn’t, or doesn’t do that it should.